Study Finds Diuretics May Raise Risk of Heart Attack

Widely used drugs for high blood pressure may increase the risk of diabetes and heart attacks by hampering the body’s ability to metabolize sugar and raising cholesterol levels, researchers from Uppsala University in Sweden said Wednesday.

The drugs, called diuretics, have been used for more than three decades to treat hypertension. Studies have found diuretics reduce the risk of stroke, congestive heart failure and kidney failure, but are unable to cut the risk of heart attack as well.

The Swedish group attempted to explain this pattern.

“We regarded diuretics as very good drugs from the beginning, and they have reduced the risk of stroke, but that is not good enough, it has not reduced the risk of heart attacks,” said Han Lithell, one of the co-authors of study.

Led by Dr. Thomas Pollare, the researchers studied a group of 50 patients who received the drug hydrochlorothiazide, a diuretic, and subsequently captopril, a newer high-blood pressure treatment, over two four-month treatment periods.

They found that hydrochlorothiazide had “adverse effects” on the levels of fat and sugar in the blood.

Reported in Today’s Journal

“It is possible, but not proved in this study, that these changes may contribute to the risk for diabetes mellitus and coronary heart disease,” the researchers report in today’s edition of the New England Journal of Medicine.

Sees Beneficial Effects

“In contrast, captopril appears to have beneficial or no effects on glucose and lipid metabolism,” they said.

Diabetes develops when the pancreas no longer produces insulin to break down sugar. It can also develop as the body grows more resistant to the action of insulin.

Captopril is sold as Capoten or Capozide by Squibb Corp. of Princeton, N.J., and the study was funded in part by Squibb. It showed that hydrochlorothiazide made the body’s insulin work even less effectively, while captopril produced a beneficial, 11% increase in insulin activity.

However, some medical experts disagreed.

“To abandon these drugs, on the basis of this kind of evidence is not justified,” said Dr. Jeffrey Cutler, a researcher at the National Heart, Lung, and Blood Institute, an arm of the Institutes of Health.

“Diuretics are the only drugs tested and shown in large trials to reduce stroke, and they are also cheap, and relatively free of disturbing side effects,” he said.